Southern Company Chairman, President, and CEO Thomas Fanning announces that the Nuclear Regulatory Commission voted 4 to 1 to approve the Atlanta-based company's request to build two nuclear reactors at its Vogtle site south of Augusta, during a news conference in Atlanta Thursday.

The federal board that regulates nuclear power in the US on Thursday voted to allow construction to proceed on the first new commercial nuclear power reactors in more than three decades.

The decision, which clears the way for two reactors at the Vogtle nuclear power site east of Atlanta, was immediately hailed as "historic" by business groups and nuclear-industry advocates. But it was condemned not only by nuclear-safety watchdog groups, but also by the chairman of the regulatory group itself.

"Ultimately, my responsibility is to make what I believe is the best decision for nuclear safety," said Gregory Jaczko, the chairman of the Nuclear Regulatory Commission (NRC) and the sole dissenting vote on the five-member panel, in a statement. "I simply cannot authorize issuance of these licenses without any binding obligation that these plants will have implemented the lessons learned from the Fukushima accident before they operate."

Following the Fukushima accident in Japan last March, an NRC special task force identified numerous safety improvements for US nuclear plants, but the commission has not acted yet to approve any of them.

To ensure that the new plants carried forward the lessons learned from that accident, Mr. Jaczko had proposed that new licensees' plants meet all post-Fukushima standards the NRC approves. The four other commissioners disagreed and overruled him, arguing that the NRC has enough tools to change standards as needed without needing to write them into licenses.

"We find ourselves in disagreement with the specific approach he offers in his dissent – namely, an across-the-board license condition requiring implementation of 'all' Fukushima-related requirements prior to operation of the Vogtle plant," the four commissioners wrote. "Such a license condition, in our view, cannot now be framed in meaningful terms."

Moreover, the license-condition approach is "unnecessary, given the myriad of regulatory tools available to the NRC to implement Fukushima-related requirements as they emerge," the commissioners added.

Nuclear-watchdog groups took issue with that line of thinking. They argue that by not requiring in the construction license that the new reactors meet post-Fukushima safety standards, the NRC made it far less likely that new standards would be incorporated at all.

It's not at all clear if post-Fukushima standards – which could require costly retrofits – meet an NRC rule that requires companies to implement safety conditions only if they meet a cost-benefit analysis standard.

"The commission should have said: 'We're not going to leave the door open for you to say 10 years later, 'It's not worth it,' " says Edwin Lyman, a nuclear physicist and reactor-safety expert at the Union of Concerned Scientists, a Washington-based nuclear-safety advocacy group. "It's actually a wise strategy that no new reactors be allowed to operate unless they can show they are in full compliance with post-Fukushima safety measures."

Other nuclear power critics noted that after the Three Mile Island (TMI) accident in 1979, the NRC refused to approve new licenses for 18 months pending completion of its safety review.

"The subsequent licenses were all contingent on adopting the TMI action plan" for safety upgrades, says Peter Bradford, who served on the commission beginning in 1977 and during the TMI crisis.

But nuclear-power advocates proclaimed today's vote "historic" and a stamp of approval for the new Westinghouse AP1000 plant design Vogtle will use. New nuclear plants would be a big boost for the nation's energy posture, they argued.

“The United States is building new nuclear energy facilities under an improved licensing process that exhaustively addresses safety considerations," Marvin Fertel, the Nuclear Energy Institute’s president and chief executive officer, said in a statement. "It also assures that the lessons learned from the industry’s licensing and construction experience are properly applied to future projects."

Karen Harbert, president and CEO of the US Chamber of Commerce's Institute for 21st Century Energy, called the NRC decision an "enormous milestone in the effort to provide safe, reliable, and clean electricity to consumers."

Currently, 104 nuclear reactors generate roughly 20 percent of the nation's power. The last time the NRC approved a such a permit was in 1978 for a plant built near Raleigh, N.C. If completed as expected around 2016, the new Vogtle reactors will cost about $14 billion.

Several antinuclear groups vowed to sue, and former NRC commissioner Mr. Bradford questioned the federal policy of making loan guarantees to finance such plants. The US Department of Energy has made $8.8 billion available for Vogtle.

"Its been clear all along that the nuclear renaissance consisted of nothing more than the number of plants governments are prepared to build on behalf of the nuclear power industry," says Bradford, now a professor at Vermont Law School in South Royalton.

"A few years ago, there were 31 plants being readied for construction," Bradford says. "Now it's four – the two at Vogtle and ... two in South Carolina. There's nothing in the pipeline after that."